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Auranofin, an FDA-approved drug for rheumatoid arthritis, has emerged as a promising antiparasitic medication in recent years. The gold(I) ion in auranofin is postulated to be responsible for its antiparasitic activity. Notably, aurothiomalate and aurothioglucose also contain gold(I), and, like auranofin, they were previously used to treat rheumatoid arthritis. Whether they have antiparasitic activity remains to be elucidated. Herein, we demonstrated that auranofin and similar derivatives, but not aurothiomalate and aurothioglucose, inhibited the growth of Toxoplasma gondii in vitro. We found that auranofin affected the T. gondii biological cycle (lytic cycle) by inhibiting T. gondiis invasion and triggering its egress from the host cell. However, auranofin could not prevent parasite replication once T. gondii resided within the host. Auranofin treatment induced apoptosis in T. gondii parasites, as demonstrated by its reduced size and elevated phosphatidylserine externalization (PS). Notably, the gold from auranofin enters the cytoplasm of T. gondii, as demonstrated by scanning transmission electron microscopy-energy dispersive X-ray spectroscopy (STEM-EDS) and Inductively Coupled Plasma-Mass Spectrometry (ICP-MS).IMPORTANCEToxoplasmosis, caused by Toxoplasma gondii, is a devastating disease affecting the brain and the eyes, frequently affecting immunocompromised individuals. Approximately 60 million people in the United States are already infected with T. gondii, representing a population at-risk of developing toxoplasmosis. Recent advances in treating cancer, autoimmune diseases, and organ transplants have contributed to this at-risk populations exponential growth. Paradoxically, treatments for toxoplasmosis have remained the same for more than 60 years, relying on medications well-known for their bone marrow toxicity and allergic reactions. Discovering new therapies is a priority, and repurposing FDA-approved drugs is an alternative approach to speed up drug discovery. Herein, we report the effect of auranofin, an FDA-approved drug, on the biological cycle of T. gondii and how both the phosphine ligand and the gold molecule determine the anti-parasitic activity of auranofin and other gold compounds. Our studies would contribute to the pipeline of candidate anti-T. gondii agents.

Unlike aromatic allenes, the hydrothiolation of aliphatic allenes has proven challenging for previously developed catalysts. Herein, a 3‐iminophosphine supported palladium catalyst is shown to be highly effective for the double hydrothiolation of aliphatic allenes, producing dithioacetals in a regioselective and atom‐efficient manner. The utility of this methodology is demonstrated for twelve new dithioacetals formed from aliphatic allenes and aryl thiols and isolated in moderate to excellent yields in all cases. [ABSTRACT FROM AUTHOR]

Despite the appeal of organic redox systems as next-generation energy-storage media, achieving high cell voltages with electrolytes based on main-group elements typically comes at the cost of reduced long-term stabilities. In this Synpacts article, we summarize our recent finding that the introduction of phosphine oxide functionalities can unlock the ability of terthiophenes to serve as robust two-electron acceptors at extreme potentials. These investigations uncovered a fundamentally new class of multielectron redox systems, capable of expanding the cell potential range achievable with organic electrolytes without compromising stability. [ABSTRACT FROM AUTHOR]

Phosphorus chemistry occupies a pivotal position in contemporary organic chemistry but significant synthetic challenges still endure. In this report, a class of electrophilic phosphiranium salts, bearing fluorinated benzyl quaternizing groups, is introduced for the direct synthesis of diversely β-functionalized phosphines. We show that, in comparison with regular quaternary phosphiranium salts, these species display the sought balance of excellent stability and high electrophilic reactivity that allow the unlocking of the C-centered ring-opening reactions with different classes of weak nitrogen-, sulfur- and oxygen protic nucleophiles. In the arena of strained heterocyclic chemistry, phosphacycles as appealing electrophilic P-containing building blocks are underestimated. Here, the authors report a class of electrophilic phosphiranium salts bearing fluorinated benzyl quaternizing groups for the direct synthesis of diverselyβ-functionalized phosphines. [ABSTRACT FROM AUTHOR]

Polymer networks have emerged as materials with widespread application, including their use in drug delivery, catalysis, and flexible electronics. They have traditionally been derived from organic building blocks using well‐developed reaction types. Advances in main group synthetic chemistry have opened the door for the production of new polymer networks, including those containing phosphorus atoms that offer the traits of Lewis basic phosphorus centers. Here, the radical‐catalyzed phosphane‐ene reaction is used to prepare (co)polymer networks from iBuPH2, trivinyltriptycene (TVT), and 1,3,5‐triallyl‐1,3,5‐triazine‐2,4,6‐trione (TTT), which are the first of their type to include TVT. Networks rich in TVT exhibited greater thermal stability and reduced network mobility compared to those rich in TTT. Despite the rigidity, 3D, and internal free volume associated with the triptycene units present in TVT‐rich networks, their swellability is similar to networks rich in TTT indicating that the presence of phosphines may be a dominating factor in the respective structure‐property relationships. [ABSTRACT FROM AUTHOR]

Phosphanes play an important role in various applications, serving as a class of organic bases with basicities spanning more than 30 orders of magnitude. Accessing comprehensive basicity data for phosphanes has been challenging due to scattered information across multiple sources and notable gaps in the existing data. In this report, we present basicities (pKaH values) of a diverse set of phosphanes, both newly measured or calculated and collected from the literature. We demonstrate that pKaH values can serve as an alternative to Tolman electronic parameters (TEP values) in evaluating the electronic properties of phosphanes. Additionally, we suggest parameters for assessing the steric properties of phosphanes without the need for preparation or calculation of metal-ligand complexes. [ABSTRACT FROM AUTHOR]

The Wittig reaction is renowned as exceptionally versatile method for converting a diversity of aldehydes and ketones into alkenes. Recently, strategies for chiral phosphine catalysis under PIII/PV=O redox cycling emerged to render this venerable transformation stereoselective. Herein, we describe that phosphine redox catalysis enables the enantioselective synthesis of pertinent biaryl atropisomers by means of a stereocontrolled arene‐forming Wittig reaction. Key to the process is the release of an endogenous base from readily accessible tert‐butyloxycarbonylated Morita–Baylis–Hillman adducts triggered by catalyst intramolecularization, permitting mild phosphine redox catalysis for atroposelective Wittig reactions. By this strategy, a broad diversity of biaryl atropisomers is obtained with up to 94 : 6 enantioselectivity. [ABSTRACT FROM AUTHOR]

Palladium‐catalyzed coupling reactions of small nucleophiles are of great interest, but challenging due to difficulties in selectivity control. Herein, we report the development of a new platform of P,N‐ligands consisting of ylide‐functionalized phosphines with aminophosphonium groups (NYPhos) to address this challenge. These phosphine ligands are easily accessible in a wide structural diversity with highly modular electronic and steric properties. Based on a family of 14 ligands the selective monoarylation of acetone as well as other challenging ketones and amides was accomplished with record‐setting activities even for aryl chlorides at room temperature including late‐stage functionalizations of drug molecules. Moreover, ammonia and other small primary amines could be coupled at mild conditions. Isolation and structure analyses of palladium complexes within the catalytic cycle confirmed that the P,N‐coordination mode is necessary to achieve the observed selectivities. It also demonstrated the facile adjustability of the N‐donor strength, which is beneficial for the targeted design of tailored P,N‐ligands for future applications. [ABSTRACT FROM AUTHOR]

A photooxidation approach to the conversion of phosphines into the corresponding phosphine oxides is reported. By taking advantage of O2 in the air as an oxidant and oxygen source, phosphine oxides were obtained efficiently in moderate to excellent yields. A four-coordinated organoboron compound was used as the photocatalyst to activate O2 to its singlet state. This photooxidation method features mild reaction conditions, broad functional-group tolerance, and a wide substrate scope. [ABSTRACT FROM AUTHOR]

Ylide‐functionalized phosphines (YPhos) have been shown to yield highly active gold catalysts owing to their high donor capacity. To examine the impact of ylide functionalization on a given ligand structure, a series of ferrocenyl diphosphines functionalized with no, one or two ylide moieties and their corresponding bimetallic gold complexes were prepared. The complexes feature an anti‐conformation of the two phosphine moieties, guaranteeing the presence of two independent metal centers. Comparative studies of the complexes in the hydroamination and hydrohydrazination of alkynes revealed a significant increase in catalytic activity for each newly introduced ylide group. The di‐YPhos ligands were revealed to be the most active precatalysts, functioning effectively even at 0.1 or 0.2 mol % catalyst loading. This catalytic efficiency was demonstrated for a series of alkynes, amines and hydrazines. [ABSTRACT FROM AUTHOR]

Quaternary phosphonium salts (QPS) are significant structural motifs in drugs, materials, and catalysts. Here, a photoactivated approach for the selective late-stage synthesis of QPS utilizing organothianthrenium salts and tertiary phosphines is presented with high yields and broad functional group compatibility. Additionally, the synthetic utility of this protocol is demonstrated by in situ generation of QPS via C–H functionalization and its fluorescence confocal imaging of mitochondrial localization in cells. [ABSTRACT FROM AUTHOR]

P‐chiral supramolecular phosphine ligands are crucial for asymmetric transformations, but their synthesis is tedious. We report a one‐step synthesis of thermally stable P‐chiral supramolecular phosphines and their performance in the asymmetric hydrogenation of functionalized alkenes. A rational designing and synthesis of (R, R)‐QuinoxP* ligated palladium complex (Pd‐2) in excellent yield is reported. This Pd‐2 catalyzed a direct P−C coupling of 2,3‐dihydro‐1‐H‐phosphindole (A1)/1,2,3,4‐tetrahydrophosphindoline (A2) with 1‐(3‐iodophenyl)urea (B1)/2‐iodo /6‐hydroxy pyridine (B2) and,produced corresponding ligands L1–L3. The P−C coupling between A1 and B2 produced 6‐(2,3‐dihydro‐1H‐phosphindol‐1‐yl)pyridine‐2(1H)‐one (L2) with an excellent enantiomeric excess of up to 99 %. L2 was found to be remarkably stable even at 150 °C and did not oxidize/hydrolyze for at least 24 hours in open air. Such thermal stability and an impediment to oxidation are unprecedented. L2 self‐assembled and produced L2−C1 (Pt), L2−C2(Pd), and L2−C3(Rh) assemblies. The utility of the self‐assembled P‐chiral ligand was demonstrated in the Rh‐catalyzed asymmetric hydrogenation (AH) of functionalized olefins. The L2−C3 catalyzed AH of functionalized alkenes and delivered chiral products with excellent enantioselectivity of >99 %. A small library of 16 substrates was subjected to AH using L2−C3 to produce chiral compounds with excellent conversion and ee. [ABSTRACT FROM AUTHOR]

Introduction: The human immunodeficiency virus (HIV) remains a significant global health concern, with a reported high infection rate of 38.4 million cases globally; an estimated 2 million new infections and approximately 700,000 HIV/ AIDS-related deaths were reported in 2021. Despite the advent of anti-retroviral therapy (ART), HIV/AIDS persists as a chronic disease. To combat this, several studies focus on developing inhibitors targeting various stages of the HIV infection cycle, including HIV-1 protease. This study aims to synthesize and characterize novel glyco diphenylphosphino metal complexes with potential HIV inhibitory properties. Method: A series of new gold(I) thiolate derivatives and three bimetallic complexes, incorporating amino phosphines and thiocarbohydrate as auxiliary ligands, were synthesized using procedures described by Jiang, et al. (2009) and Coetzee et al. (2007). Structural elucidation and purity assessment of the synthesized compounds (1-11) were conducted using micro-analysis, NMR, and infrared spectrometry. Results and Discussion: Using molecular modeling techniques, three of the metal complexes were identified as potential HIV protease inhibitors, exhibiting strong binding affinity interactions with binding pocket residues. These inhibitors demonstrated an ability to inhibit the flexibility of the flap regions of the HIV protease, similar to the known HIV protease inhibitor, darunavir. This study sheds light on the promising avenues for the development of novel therapeutic agents against HIV/AIDS. [ABSTRACT FROM AUTHOR]

An approach for the preparation and stabilization of primary phosphine oxides is presented complementing previous methods of in situ generation. Specifically, RP(O)H2 where R=benzyl (Bn), cyclohexyl (Cy), 2‐naphthyl (2‐Naph), phenyl (Ph), tert‐butyl (t‐Bu) was prepared by controlled oxidation of the corresponding primary phosphine in presence of ferrocene as stabilizing reagent. The primary phosphine oxides were characterized using NMR and MS and studied in twofold hydrophosphorylation of diketones. The domino‐phospha‐aldol reaction catalysed with 5 mol% of sodium methoxide yielded five‐, six‐ and seven‐membered heterocyclic tertiary phosphine oxides with a high degree of stereoselectivity, as confirmed by single X‐ray diffraction. [ABSTRACT FROM AUTHOR]

Synthesis of new polysubstituted furans incorporating reactive phosphorus ylides or N‐acyliminophosphoranes was achieved by the heterocyclization of flexible α‐acyl ketene dithioacetals. This one‐pot tandem reaction was initiated by acyl‐directed desulfurative Sonogashira coupling, followed by 1,6‐addition of phosphine to the in situ‐generated enynone and subsequent 5‐exo‐dig cyclization, as well as phosphoranation. The selectivity toward the two products, i. e. α‐phosphorus ylides vs. α‐N‐acyliminophosphoranes‐substituted furans, was determined by both electron‐deficient acetylenes and copper salts. [ABSTRACT FROM AUTHOR]

The formation of phosphorus‐rich alanes featuring butterfly‐like geometries is achieved. The two‐electron reduction products feature a unique P42− structure and can act as a source of P3−. The treatment of these phosphorus containing products with electrophiles under mild conditions results in the formation of different phosphines. This approach eliminates the need for high temperatures and/or high pressures, which are commonly required in industrial processes for the preparation of useful phosphines.The activation and further functionalization of white phosphorus (P4) by main group complexes has become an increasingly studied topic in recent times. Herein, we report the controlled formation of phosphorus‐rich alanes featuring butterfly‐like geometries from the selective reaction of P4 with dialumenes, ([L(IiPr)Al]2) (1: L=Tripp=2,4,6‐iPr3C6H2; 2: L=tBu2MeSi; IiPr=[MeCN(iPr)]2C)). The two‐electron‐reduction product of P4 features a P42− structure and is shown to be able to act as a source of P3−. Treatments of different electrophiles (e.g. chlorotrimethylsilane (Me3SiCl), iodotrimethylsilane (Me3SiI), HCl, or acetyl chloride (CH3COCl)) with these alanes under mild conditions gave the corresponding phosphines (e.g. P(SiMe3)3, PH3, or P(COCH3)3). [ABSTRACT FROM AUTHOR]

Asymmetric ring-expansion reactions of silacyclobutanes (SCBs) with alkynes have evolved as one of the powerful protocols for the construction of silicon-stereogenic compounds. However, the achievement of highly enantio-selective annulation of SCBs with terminal alkynes remains a challenge. Herein, we report a rhodium-catalyzed asymmetric annulation reaction of SCBs with terminal alkynes, which relies on the newly identified chiral sul-finamide phosphine ligand Ming-Phos. This catalytic system exhibits unique effects under mild conditions, leading to the direct synthesis of structurally diverse chiral silacycles in moderate to good yields with high enantioselectivities (up to 95% ee). [ABSTRACT FROM AUTHOR]

Mono- and binuclear Cu(I) complexes were isolated employing 2,1,3-benzoselenadiazole (BSeD) as the N-donor ligand, and triphenylphosphine or bis[(2-diphenylphosphino)phenyl] ether (DPEphos) as P-donors. Then, 77Se NMR was measured for the free ligand and the corresponding Cu(I) derivatives, and the related signal was downshifted by 12.86 ppm in the case of [Cu(BSeD)(PPh3)2(ClO4)], and around 15 ppm for the binuclear species. The structure of [Cu(BSeD)(PPh3)2(ClO4)] and [Cu2(μ2-BSeD)(DPEphos)2(ClO4)2] was confirmed by single-crystal X-ray diffraction. The geometry of the Cu(I) complexes was optimized through DFT calculations, and the nature of the Cu···O interaction was investigated through AIM analysis. The three Cu(I) complexes were characterized by intense absorption under 400 nm and, after being excited with blue irradiation, [Cu(BSeD)(PPh3)2(ClO4)] and [Cu2(μ2-BSeD)(PPh3)4(ClO4)2] exhibited weak red emissions centered at 700 nm. The lifetimes comprised between 121 and 159 μs support the involvement of triplet excited states in the emission process. The photoluminescent properties of [Cu(BSeD)(PPh3)2(ClO4)] were supported by TDDFT computations, and the emission was predicted at 710 nm and ascribed to a metal-to-ligand charge transfer (3MLCT) process, in agreement with the experimental data. [ABSTRACT FROM AUTHOR]

This article discusses the synthesis of a new P-chiral phospholene core-based ligand called LemPhos. The authors propose a method using a chiral diene to create diastereomers that are easier to separate, allowing for the production of P-chiral ligands. The ligands are synthesized and characterized, and their application as catalysts in asymmetric hydrogenation reactions is explored. The document also includes experimental procedures and spectroscopic data for the synthesized compounds. The research is dedicated to the memory of Stanisław Lem, a renowned science-fiction writer. [Extracted from the article]

1,3‐Enynes with conjugated alkene and alkyne moieties are attractive building blocks in synthetic chemistry. However, neither 4,1‐hydrophosphination nor dihydrophosphination of 1,3‐enynes has been reported. In this paper, the divalent ytterbium and calcium amide complexes supported by silaimine‐functionalized cyclopentadienyl ligands (C5Me4‐Si(L)=NR) were developed, which successfully catalyzed the efficient single and double hydrophosphination of 1,3‐enynes with diarylphosphines. The hydrophosphination reactions selectively produced homoallenyl phosphines and (E)‐propenylene diphosphines, respectively. This work demonstrated the potential of hemilabile silaimine‐Cp ligands in the supporting the efficient and selective rare‐ and alkaline‐earth catalysts. [ABSTRACT FROM AUTHOR]

An efficient phosphine-catalyzed dearomative [3+2] annulation of 4-nitroisoxazoles with allenoates or Morita–Baylis–Hillman carbonates has been established for the convenient synthesis of bicyclic isoxazoline derivatives. This reaction approach showed a broad substrate scope, high functional group compatibility, and excellent regioselectivity and diastereoselectivity. Furthermore, the success at the gram-scale and synthetic applications of the obtained compound 3a demonstrate the great potential of this methodology for practical applications in organic synthesis. [ABSTRACT FROM AUTHOR]

The coordination of anionic donors is involved at various stages of catalytic cycles in transition‐metal catalysis, but control over the spatial positioning of anions around a metal center is a challenge in coordination chemistry. Here we show that regioisomeric phosphine‐carboxylate ligands provide spatial anion control on palladium(II) centers by favoring either κ2, cis‐κ1, or trans‐κ1 coordination of the carboxylate donor. Additionally, the palladium(II) carboxylates, which contain a methyl donor, upon protonation, deliver metal‐alkyl complexes that feature a coordinated carboxylic acid. Such complexes can be considered as models for the minima that follow the concerted metalation‐deprotonation transition state for C−H activation. The predictability of the coordination modes is further demonstrated on silver(I) and copper(I) centers, for which less common structures of mononuclear and dinuclear complexes can be obtained by using spatial anion control. Our results demonstrate the potential for spatial control over carboxylate anions in coordination chemistry. [ABSTRACT FROM AUTHOR]

Polysubstituted acrylamides are ubiquitous in bioactive molecules and natural products. However, synthetic methods for the assembly of these important motifs remain underdeveloped. Herein, we report the expedient synthesis of structurally diverse and synthetically challenging polysubstituted acrylamides from readily available aromatic amines, cyclopropenones (CpOs), and aryl halides via the synergistic merging of nucleophilic phosphine-mediated amidation and palladium-catalyzed C–H arylation. The reaction is scalable, and some obtained acrylamides proved to be solid state luminogens with obvious aggregation-induced emission (AIE) properties, demonstrating the synthetic potential in drug discovery and material development. [ABSTRACT FROM AUTHOR]

We have found that amines significantly accelerate iodide substitution in CpFe(CO)2I (1) (Cp = η5-cyclopentadienyl) with phosphines and allow the synthesis of new complexes that are not available through reactions carried out without an amine. The reaction of equimolar amounts of 1 and triphenylphosphine in toluene containing DIPA afforded [CpFe(CO)2PPh3]+I− within 5 min at room temperature in 72% yield (90% after 24 h). DIPA and pyrrolidine gave the highest yields of the tested amines. We performed a similar reaction using model bisphosphines 1,3-bis(diphenylphosphino)ethane (dppe) and 1,1′-bis(diphenylphosphino)ferrocene (dppf). The products depended on the reagent ratio and bore the CpFe(CO)2 moiety coordinated to one or two phosphine phosphorus atoms. Chelates [CpFe(CO)(dppe)]+I− (4) and [Cp2Fe2(CO)4(dppe)]2+2I− (5) were formed in 72% and 98% yield, respectively. We also performed the DIPA-catalyzed reaction of 1 with triethyl phosphite and obtained the product of an Michaelis–Arbuzov-like rearrangement, CpFe(CO)2[P(O)(OCH2CH3)2] (11). All complexes were characterized with spectroscopic analysis by NMR, FT-IR, and ESI-MS, and by XRD for three complexes. To clarify the reaction mechanism, we performed theoretical calculations of the intermolecular interactions between 1 and amine molecules. We propose two possible reaction mechanisms to explain the formation of products. [ABSTRACT FROM AUTHOR]

We reported a chiral oxamide‐phosphine ligand (COAP−Ph)‐Pd‐catalyzed asymmetric [3+2] cycloaddition reaction between vinyl cyclopropane compounds derived from 1,3‐indanedione and 2‐vinylcyclopropane‐1,1‐dicarboxylates with cyclic sulfonyl 1‐azadienes. The corresponding reactions provided a series of enantiomerically active spiro cyclopentane‐indandione and cyclopentane structures bearing three consecutive stereogenic centers in good yields with good diastereo‐ and enantioselectivity. The COAP−Pd complex serves not only to promote generation of chiral π‐allyl‐palladium intermediates and induce the asymmetry of the reaction, but also depress the background reaction. [ABSTRACT FROM AUTHOR]

Herein, we present a CuI-dimer, [CuI{Ph2PC6H4C(O)NC6H4PPh2-o}]2, which catalyzed direct C(sp3)–H homocoupling of benzyl and cycloalkane derivatives with excellent yields and regio-selectivity. The method is very simple and tolerates various functionalities. Synergistic metal–ligand cooperativity was observed in Cu–N bond cleavage and protonation of nitrogen, and facilitates a bifunctional pathway, minimising the free energy corrugation for catalytic intermediates. [ABSTRACT FROM AUTHOR]

The use of Pd‐catalysts based on biaryl phosphacycles allowed facile Suzuki‐Miyaura couplings of a wide range of deactivated, sterically hindered, and heteroaryl chloride substrates with aryl boronic acids. Notably, the strongly electron‐deficient and sufficiently hindered biaryl phosphacycle ligand 7 consistently demonstrated effective performance. [ABSTRACT FROM AUTHOR]

Trialkyl phosphines PMe3 and PEt3 catalyze the 1,2‐cis‐diboration of 1,3‐butadiynes to give 1,2‐diboryl enynes. The products were utilized to synthesize 1,1,2,4‐tetraaryl enynes using a Suzuki‐Miyaura protocol and can readily undergo proto‐deborylation. [ABSTRACT FROM AUTHOR]

Since the discovery of the palladium/norbornene (Pd/NBE)‐catalyzed ortho amination in 2013, escaping the limitation of only yielding tertiary anilines has been a long‐standing challenge. Here, we describe that, by carefully choosing the phosphine ligand and NBE mediator, the installation of a N‐mono‐alkylamino group becomes feasible. The reaction tolerates a wide range of aryl iodide substrates and various N‐mono‐tertiary alkylamine‐derived electrophiles. Both ipso alkenylation and alkynylation can be realized. The synthetic utility of this method is exemplified by the formation of primary amino group via selective deprotection and streamlined access to N‐heterocycles. Preliminary success of installing a bulky N‐secondary alkylamino group and a mechanistic understanding of the decomposition pathways of mono N‐alkylamine electrophiles have been obtained. [ABSTRACT FROM AUTHOR]

A series of new pyrazole‐alkyl phosphine ligands with varying cycloalkyl ring sizes that enable additive‐free regio‐ and chemoselective C─H arylation of heterocycles are reported. Excellent α/β selectivity of various heterocycles such as benzo[b]thiophene, thiophene, furan, benzofuran, and thiazole can be achieved using these ligands, along with excellent chemoselectivity of C─Cl over C─OTf of chloroaryl triflates. Mechanistic studies supported by both experimental findings and density functional theory calculations indicate that the pyrazole phosphine ligands with optimal ring sizes allow the reaction to proceed with a lower energy barrier via a concerted metalation–deprotonation pathway. [ABSTRACT FROM AUTHOR]

α-Chiral alkyl phosphines are privileged structural motifs with a wide application in organic and medical synthesis. It is highly desirable to develop stereoselective methods to prepare these enantioenriched molecules. The incorporation of C(sp³)-H functionalization and chiral phosphine chemistry is much less explored, probably because of the weak reactivity of C(sp³)-H bonds and/or the challenging site-and stereoselectivity issues. Herein, we disclose a synergistic catalysis system to enable an enantioselective radical addition process of α-substituted vinylphosphine oxides. An array of diverse α-chiral alkyl phosphors compounds is smoothly accessed by using the readily available chemicals as the inert C(sp³)-H bond reagent, such as sulfides, amines, alkenes, and toluene derivatives, exerting remarkable chemo-, site-, and enantioselectivity. On the basis of the mechanistic studies, both the C(sp³)-H bond activation and the stereochemistry-determining step are proposed to involve a single-electron transfer/proton transfer process. [ABSTRACT FROM AUTHOR]

This document provides experimental results for the synthesis of various compounds using a general procedure. The compounds include 5-Pivalamidooctyl Benzoate, N-(1-(2-Methoxyphenoxy)heptan-4-yl)pivalamide, N-(1-(3-(Trifluoromethyl)phenyl)heptan-4-yl)pivalamide, 4-Pivalamidoheptyl 2-Bromobenzoate, N-(8-(2,6-Dichlorophenoxy)octan-4-yl)pivalamide, 6-Pivalamidononyl 2-(2-Fluoro-[1,1′-biphenyl]-4-yl)propanoate, 7-Pivalamidodecyl Thiophene-2-carboxylate, and 4-Pivalamidoheptyl 1-Methyl-1H-pyrrole-2-carboxylate. The compounds' yields, physical properties, and spectroscopic data, including NMR and HRMS, are reported. The document does not provide any additional information or context beyond the experimental results. [Extracted from the article]

Homogenous catalysis is an essential tool within the commercial manufacture of bulk and fine chemicals. Within this, phosphine ligands, such as tricyclohexylphosphine, otherwise known as CYTOP® 366, are a crucial component. When designing a pathway to your ligand of choice, some key considerations include safety, yield and quality, but at commercial volumes we must also balance cost and consider the technologies readily available. Herein, we report the synthetic route that was chosen to manufacture tricyclohexylphosphine at commercial scale. We also consider, with the use of computational calculations, why traditional hydrophosphination methods failed, where the selected pathway succeeded. [ABSTRACT FROM AUTHOR]

A sensitive and stable spray for thin layer chromatography of acyl-CoA and other thio-compounds has been evaluated. CoA, down to 1 nmol, is readily revealed and by pre- or post-treatment with hydroxylamine or tris(2-carboxyethyl)phosphine, thioesters or disulfides respectively can be stained as well. [ABSTRACT FROM AUTHOR]

Photosensitizer design of luminescent terbium (Tb(III)) complexes with narrow bandwidths is important for advancing luminescent materials. In this study, we report an effective photosensitizer model in a thermally populated lowest excited triplet (T1) state during Tb(III) emission. The Tb(III) complex comprises a Tb(III) ion (serving as an emission center), hexafluoroacetylacetonates (acting as photosensitizer ligands), and bulky cyclohexyl group-attached phosphine-oxide-type ligands (functioning as an oxygen barrier system). Emission properties including emission and excitation spectra, ligand-excited emission quantum yields, and emission lifetimes were evaluated in the absence and presence of oxygen. Coordination geometry structures were determined through analysing single-crystal structures. The electronic structure based on 4f-orbitals was estimated from radiative rate constants and quantum chemical calculations. The bulky phosphine oxide ligand not only provides an oxygen barrier system but also induces an electronic structural modulation based on 4f-orbitals, allowing for effective photosensitized Tb(III) emission in a thermally populated ligand T1 state in air. [ABSTRACT FROM AUTHOR]

Luminescent organic radicals, especially those with photoactivated circularly polarized luminescence (CPL) features, hold great significance for cutting‐edge optoelectronic applications, but their development still remains a challenge. In this study, we propose a novel strategy to achieve photoactivated CPL radicals by bonding two phosphine centers within an axial chiral system, yielding a compound of R/S‐5,5‐bis(diphenylphosphino)‐4,4′‐bibenzo[d][1,3]dioxole (R/S‐BDP). The photoactivated R/S‐BDP molecules in polymer matrix display a robust quantum yield of 19.8 % and a dissymmetry factor (glum) of 1.2×10−4, marking this work as the first example of photoactivated CPL radicals. Furthermore, the glum is improved to 1.0×10−2 by using a liquid crystal as host. Experimental and theoretical analyses reveal that R/S‐BDP molecules, endowed with double phosphine cores in axial chirality, offer a direct way for intramolecular electron transfer upon photoirradiation. This leads to the generation of radical ionic pairs, which subsequently trigger the donor‐acceptor arrangement through intermolecular electron transfer, thereby resulting in stable radical emission. The extended photoactivated BDP‐F exhibits a remarkably high quantum efficiency of 57.8%. Ultimately, the distinctive photo‐responsive CPL radical luminescence has been successfully used for information displays and anti‐counterfeiting. [ABSTRACT FROM AUTHOR]

Despite the simplicity and abundance of ethylene, its practical application presents significant hurdles due to its nature as a highly flammable gas. Herein, a strategic use of easily handled vinyl ether is reported as a latent ethylene surrogate achieved via a spin‐center shift (SCS) pathway, enabling the successful three‐component reaction that bridges heteroarenes and various coupling partners, including sulfinates, thiols, and phosphine oxides. Through a photoredox catalytic process, α‐oxy radicals are generated by combining various radicals with phenyl vinyl ether, which are subsequently added to N‐heteroarenes. Subsequently, the radical‐mediated SCS pathway serves as the driving force for C─O bond cleavage, effectively engaging the phenoxy group as a leaving group. In addition, by broadening the utility of the method, a valuable synthon is provided for efficient C─H vinylation of N‐heteroarenes following sulfonyl group elimination. This approach not only enriches the toolbox of synthetic methodology but also provides a more streamlined alternative, circumventing the challenges associated with direct ethylene gas usage. The versatility of the method, particularly evident in late‐stage functionalizations of medicinally relevant molecules and peptides, underscores its capability to produce invaluable three‐component compounds and vinylated N‐heteroarene derivatives. [ABSTRACT FROM AUTHOR]

Described herein is the successful crystallization‐induced dynamic resolution (CIDR) of an α‐lithiated phosphine borane utilizing the easily accessible and inexpensive ligand (R,R)‐TMCDA. Starting from the essential P‐prochiral building block dimethyl phenyl phosphine borane we were able to obtain phosphine boranes in yields up to 80 % and e.r. up to 98 : 2 by crystallization of the lithiated intermediate prior to the trapping reaction. NMR‐based deuterium labeling experiments indicate that the epimerization in solution is based on the intermolecular proton transfer between nonlithiated phosphine borane and the corresponding lithiated intermediate, rendering the presence of the remaining starting compound in an optimized solvent mixture the main factor for successful enantioselective synthesis. Quantum chemical calculations using different model systems based on solid state structures confirm these experimental results. By gaining insights into the epimerization mechanism, essential principles for CIDR of lithiated phosphine boranes are elucidated that may be expanded to other important P‐stereogenic compounds and simple chiral amines. [ABSTRACT FROM AUTHOR]

The electronic properties, coordination chemistry and reactivity of metal complexes of a planar (C2v symmetric) acridane‐derived geometrically constrained phosphine, P(NNN), are described. On complexation to metal centers, the phosphine was found to adopt a distorted trigonal pyramidal structure with a high barrier to pyramidal inversion (22.3 kcal/mol at 298 K for Au[P(NNN)]Cl). Spectroscopic data and theoretical calculations carried out at the density functional level of theory indicate that P(NNN) is a moderate σ‐donor, with significant π‐acceptor properties. Despite the distortion undergone by the phosphorus atom on coordination to metal centers, the P(NNN) ligand retains its ability to react with small molecule substrates with polar E−H bonds (MeOH, NH2Ph, NH3). It does so in a concerted fashion across one of the P−N bonds, and reversibly in the case of amine substrates. This cooperative bond activation chemistry may ultimately prove beneficial in catalysis. [ABSTRACT FROM AUTHOR]

Phosphine ligands are widely used in the manufacture of small molecule active pharmaceutical ingredients, for they play a key role in transition-metal-catalyzed cross-coupling. However, chromatographic analysis of phosphine ligands can be challenging because of the easily oxidizable nature of this class of compounds. This manuscript describes an out-of-specification (OOS) investigation study of XPhos raw material analysis by high performance liquid chromatography (LC). It is concluded that on-column degradation/oxidation is the culprit behind this OOS result. In addition, a slightly modified yet much improved new LC method is developed by adding a trace amount of tris(2-carboxyethyl)phosphine (TCEP) into the aqueous mobile phase. TCEP is also a phosphine compound and is commonly used as a reducing reagent in molecular biology. The trace amount of TCEP serves as a surrogate reagent to passivate the LC column and eliminate the on-column degradation/oxidation. As a result, a much more robust performance is achieved with greatly improved method precision and sensitivity. This is a general approach and can be applied to the LC analysis of many other phosphine ligands in the same manner. [ABSTRACT FROM AUTHOR]

The addition of Na[BArF24] (BArF24 = tetrakis(3,5-bis(trifluoromethyl)phenyl)borate) to [Pd(PP)Cl2] (PP = 1,1′-bis(phosphino)ferrocene ligands) compounds results in the loss of a chloride ligand and the formation of the dimeric species [Pd2(PP)2(μ-Cl)2][BArF24]2. In most cases, the addition of a monodentate phosphine, PR3, to these dimeric species leads to cleaving of the dimer and formation of [Pd(PP)(PR3)Cl][BArF24]. While these reactions are readily observed via a significant color change, the 31P{1H} NMR spectra offer more significant support, as the singlet for the dimer is replaced with three doublets of doublets. The reaction seems to take place for a wide range of PR3 ligands, although there do appear to be steric limitations to the reaction. The compounds were thoroughly characterized by NMR, and X-ray crystal structures of several of the compounds were obtained. In addition, the ferrocenyl backbone of the 1,1′-bis(phosphino)ferrocene ligands provides an opportunity to examine the oxidative electrochemistry of these compounds. In general, the potential at which oxidations of these compounds occurs shows a dependence on the phosphine substituents. [ABSTRACT FROM AUTHOR]

Tris(hydroxymethyl)phosphine oxide, (HOCH2)3PO (THPO), is recognized as an efficient flame-retardant polyol and a derivative of PH3 – an environment-friendly, halogen-free source for phosphorus compounds and polymers. Synthesis and industrial production of THPO are based on straightforward oxidation of tris(hydroxymethyl)phosphine, (HOCH2)3P (THP), or neutralized tetrakis(hydroxymethyl)phosphonium chloride (THPC), or sulfate (THPS), by air/O2 or H2O2. In alkaline aqueous media, THP is oxidized by water with liberation of H2. As an alcohol, THPO readily reacts with isocyanates, epoxides, aziridines, and carboxylic acid derivatives, and is widely used as crosslinker or chain-extender to produce flame-retardant polyurethanes, polyethers, polyesters, and composite materials. Similarly, with compounds containing E–Cl bonds (E = P, Si, and S), THPO forms a variety of flame-retardant P/E-compounds or polymers. Condensation of THPO with phenols proceeds via cleavage of a P–C bond of THPO and liberation of CH2O that leads to flame-retardant THPO-phenol resins. With functionalized alkyl halides, THPO forms tris(alkoxymethyl)phosphine oxide monomers containing, for example, pendant allyl, propargyl, or silane groups. Halogenation of THPO leads to tris(chloromethyl)phosphine oxide, (ClCH2)3PO, or tris(bromomethyl)phosphine oxide, (BrCH2)3PO, useful for syntheses of multifunctional organophosphorus compounds, for example, tris(aminomethyl)phosphine oxide, (NH2CH2)3PO, and phosphorus-containing podands. Similar to THPO, tris(hydroxymethyl)phosphine sulfide, (HOCH2)3PS, is used in preparation of flame-retardant components for polymers, and, in synthesis of asymmetric phosphorus compounds. [ABSTRACT FROM AUTHOR]

Crown ethers are cyclic polyethers of varied ring sizes. The ability to bind to cations of specific size and charge is based on the ring size, donor atoms present in the crown cavity, and geometry. The host-guest chemistry of crown ethers is further enriched by the introduction of other donor atoms into the crown cavity. For example, aza-crown ethers are crown ethers wherein one or more oxygen atoms are replaced by nitrogen donors. The replacement of donor atoms appreciably alters the ability of the crown cavity to host guest molecules. Phosphorus donors can be introduced to the crown ethers on the periphery to generate hybrid ligands. In these hybrid "CrownPhos" ligand systems, the crown cavity selectively binds to hard cations and phosphorus donors preferentially bind to soft transition metal centers. The presence of guest cations in the crown ether cavity can alter the steric and electronic properties of the phosphorus donors and thereby modulate catalytic ability. The current review focuses on various synthetic and catalytic aspects of crown ethers, aza-crown ethers, and thia-crown ethers appended with phosphorus donors on the periphery. Crownphos: Crown ethers decorated with tertiary phosphorus donors. The details of syntheses, reactivity, host-guest chemistry, and catalytic activities of functionalized crown ethers with phosphorus donors reported in the literature are discussed in the review. [ABSTRACT FROM AUTHOR]

A biradical formed by coordination of the organogold derivative of a nitronyl nitroxide radical with 1,1′-bis(diphenylphosphino)ferrocene was obtained. According to X-ray diffraction data, the Au—Au distance in the biradical structure is short (3.372 Å). The O atoms of paramagnetic groups form short intramolecular contacts with H atoms of cyclopentadienyl anions (2.360 and 2.581 Å) and with methyl H atoms (2.280 and 2.525 Å), as well as intermolecular contacts with H atoms of methyl groups (2.462 and 2.610 Å). Using cyclic voltammetry, it was established that the oxidation of the biradical occurs reversibly in three stages at potentials equal to −34, 232, and 845 mV vs. Ag/AgCl. Density functional calculations and the QTAIM and NBO analyses revealed that there is a weak noncovalent bond between gold atoms in the biradical complex due to partial transfer of an electron from the 5d orbital of one AuI ion to the 6s orbital of the other AuI ion. A weak intramolecular antiferromagnetic exchange interaction (J/kB ≈ −20 K) in the crystal structure was predicted. [ABSTRACT FROM AUTHOR]

Practical advances in Ni-catalyzed Suzuki-Miyaura cross-coupling (SMC) have been limited by a lack of mechanistic understanding of phosphine ligand effects. While bisphosphines are commonly used in these methodologies, we have observed instances where monophosphines can provide comparable or higher levels of reactivity. Seeking to understand the role of ligation state in catalysis, we performed a head-to-head comparison study of C(sp2)-C(sp2) Ni SMCs catalyzed by mono and bisphosphine precatalysts using six distinct substrate pairings. Significant variation in optimal precatalyst was observed, with the monophosphine precatalyst tending to outperform the bisphosphines with electronically deactivated and sterically hindered substrates. Mechanistic experiments revealed a role for monoligated (P1Ni) species in accelerating the fundamental organometallic steps of the catalytic cycle, while highlighting the need for bisligated (P2Ni) species to avoid off-cycle reactivity and catalyst poisoning by heterocyclic motifs. These findings provide guidelines for ligand selection against challenging substrates and future ligand design tailored to the mechanistic demands of Ni-catalyzed SMCs.

Utilizing the W(CO)5 group as a promoter, we have established a straightforward pathway for the conversion of simple 1-alkyl-1,2-diphospholes to P,P-bidentate caged phosphines via [4+2] cycloaddition reactions. Furthermore, during the course of our investigation, we have observed a rare instance of isomerization, wherein the W(CO)5 migrates between the two phosphorus atoms in pentacarbonyl(1-alkyl-1,2-diphosphole)tungsten(0). This intriguing phenomenon has been thoroughly investigated using variable-temperature 31P NMR spectroscopy. [ABSTRACT FROM AUTHOR]

Two mixed peri-substituted phosphine-chlorostibines, Acenap(PiPr2)(SbPhCl) and Acenap(PiPr2)(SbCl2) (Acenap = acenaphthene-5,6-diyl) reacted cleanly with Grignard reagents or nBuLi to give the corresponding tertiary phosphine-stibines Acenap(PiPr2)(SbRR') (R, R' = Me, iPr, nBu, Ph). In addition, the Pt(II) complex of the tertiary phosphine-stibine Acenap(PiPr2)(SbPh2) as well as the Mo(0) complex of Acenap(PiPr2)(SbMePh) were synthesised and characterised. Two of the phosphine-stibines and the two metal complexes were characterised by single-crystal X-ray diffraction. The peri-substituted species act as bidentate ligands through both P and Sb atoms, forming rather short Sb-metal bonds. The tertiary phosphine-stibines display through-space J(CP) couplings between the phosphorus atom and carbon atoms bonded directly to the Sb atom of up to 40 Hz. The sequestration of the P and Sb lone pairs results in much smaller corresponding J(CP) being observed in the metal complexes. QTAIM (Quantum Theory of Atoms in Molecules) and EDA-NOCV (Energy Decomposition Analysis employing Naturalised Orbitals for Chemical Valence) computational techniques were used to provide additional insight into a weak n(P)→σ*(Sb-C) intramolecular bonding interaction (pnictogen bond) in the phosphine-stibines. [ABSTRACT FROM AUTHOR]

Phosphine ligands play a crucial role in homogeneous catalysis, allowing fine-tuning of the catalytic activity of various metals by modifying their structure. An ultimate challenge in this field is to reach controlled modulation of catalysis in situ, for which the development of phosphines capable of photoswitching between states with differential electronic properties has been proposed. To magnify this lightinduced behavior, in this work we describe a novel phosphine ligand incorporating two dithienylethene photoswitchable moieties tethered to the same phosphorus atom. Double photoisomerization was observed for this ligand, which remains unhindered upon gold(I) complexation. As a result, the preparation of a fully ring-closed phosphine isomer was accomplished, for which amplified variation of phosphorus electron density was verified both experimentally and by computational calculations. Accordingly, the presented molecular design based on multiphotochromic phosphines could open new ways for preparing enhanced photoswitchable catalytic systems. [ABSTRACT FROM AUTHOR]

Under the catalysis of a Cu(I) or Ag(I) salt with a chiral diphosphine ligand, the enantioselective nucleophilic ring opening of racemic 2‐styrenylaziridines via kinetic resolution or dynamic kinetic asymmetric transformation (DyKAT) and of meso aziridines via desymmetrization with alcohols was realized. The reaction provided a range of chiral vicinal amino ether derivatives in 47%‐98% yields and with 50%–98% ee. The reaction could be extended to aliphatic carboxylic acids as nucleophiles. The synthetic utility was demonstrated in a four‐step formal synthesis of a diastereomer of the antirythmetic agent vernakalant. [ABSTRACT FROM AUTHOR]